Halina bucklandi Bowerbank, 1858.

Pachastrellidae (?) with calthrops or dichocalthrops as megascleres and possessing irregular acanthomicrorhabd-like sanidasters with a thick central axis relative to the actines; further microscleres may include smooth toxa-like forms and aster-like compressed forms; no structural oxea megascleres.

Many authors have pointed out the similarities of Dercitus and Stoeba, the distinction of which rests entirely on the presence of unique toxa-like microscleres in the type species of the former. The similarities are the shape and size of the calthrops/short-shafted triaenes, the shape of the irregular sanidasters, the absence of any structure in the skeleton, the compressible liver-like texture, and the presence of large cells (60 µm) with inclusions reported for various Stoeba species as well as Dercitus bucklandi. The majority of past authors recognized only Dercitus, but Maldonado (2002) insisted on retaining the distinction at the genus level. Since there are dozens of species conforming to the above given definition and only a single North Atlantic species possesses the toxas, it appears unnecessarily formal to keep the use of two genus names for such similar species. It also would confound biogeographical analysis having a single unique character place an endemic genus in an area of the world (Celtic Seas and Lusitanian waters) where such higher taxa endemism in sponges is virtually nonexistent. Ultimately, we need independent molecular evidence to demonstrate that both are members of the same clade, but pending such results, we propose here for practical reasons to lower the status of the genera Dercitus and Stoeba to the level of subgenera. Dercitus being the senior name, the subgenera will be Dercitus (Dercitus) and Dercitus (Stoeba). A third subgenus proposed is the suppressed Halinastra de Laubenfels (1936). The subgenera will be defined below and are keyed out in Fig. 1.

Calthrops are characteristically variable in size (cladi measuring from 25 – 648 µm), and shape, with conical-straight, curved, stunted, deformed, bifid cladi, frequently one of the cladi being longer than the others, sometimes lacking one (‘tripods’) cladus or with one or more reduced cladi, occasionally with five or more cladi. Short-shafted dichotriaenes (dichocalthrops) are present in twelve of the currently named and recognized species, and in five of these have replaced the calthrops entirely. When both megasclere types are combined in a single species, dichocalthrops are often distinctly smaller than the calthrops and the proportion of the two varies among individuals of the species.

Natural products: three unrelated compounds with biological actitivity, such as anti-tumor or antibiotic activity, have been extracted from species of Dercitus, viz. methylaplysinopsins from a Belize specimen of Dercitus sp. (cf. Djura and Faulkner 1980) and the acridine alkaloid dercitine and a dimethyldihydroxylindoliniumchloride from Dercitus (Stoeba) bahamensis sp. n. (Gunawardana et al. 1988; Burres et al. 1989; Kohmoto et al. 2005 as Dercitus sp.). The furanosesterpene shinsonefuran was reported from Dercitus (Halinastra) japonensis sp. n. (Phuwapraisirisan et al. 2004, as Stoeba extensa).

Dercitus possessing toxa-like microscleres and a single category of irregular sanidasters.

Halina bucklandi Bowerbank, 1858

Schizoholotype (2 slides, one with dissociated spicules, the other with section at right angles to surface): NHM collection, Bwbk. 542 (labeled as Battersbyia bucklandi, Hymeniacidon bucklandi), part of holotype BMNH 1877.5.21.142 (wet, fragment examined); locality presumed to be Abbey Bay, near Torquay, Devon, England (but this is not indicated on the labels).

Holotype of Dercitus niger Carter, 1871 (dry) BMNH 1895.4.27.1–6 (Fig. 3) ; dry schizotype ZMB 3046, (including 17 slides); locality Straight Point, Budleigh–Salterton, South Devon.

(amalgamated from various descriptions of material from the British Isles and NW France). Cushion-shaped to massive-lobose (Figs 2A, 3A), filling crevices in vertical rock faces. Size frequently over 5cm2. Black to dark grey-brown externally. Surface smooth but often has ridges looking like stretch-marks. The surface is usually concave. Apertures (oscules?) are flush with the surface, variable in size and usually collected into groups towards the centre of the sponge. Consistency moderately firm but compressible and spongy when in situ, liver-like in preserved condition.

Skeleton: Main skeleton of confused, randomly arranged calthrops, a layer of sanidasters and many toxas occur near the surface, but these also occur in the choanosome. There are many large pigment cells (?) with black inclusions evident in sections.

Spicules: Calthrops, toxiform microscleres, sanidasters.

Calthrops (Figs 2B, 3B–C), often with axial canals seen clearly, occasional bifid cladi or with angulated curve, rarely with 5 cladi, size of cladi: 80–218.9–305 × 12–28.1–48 µm, cladomes 120–311.3–480 µm.

Smooth toxiform microscleres (Figs 2C, 3D, 5a–e), often slightly swollen near the apices, occasionally with irregular side branches (Fig. 2C) : 51–86.8–111 × 1–2 µm.

Sanidasters (Figs 2D, 3E) relatively robust with strong spines in ‘mature’ condition : 22–25.7–31 × 0.5–5.2–7 µm (spines included in width).

In crevices in vertical rock faces in clean water. Particularly common on limestone substrata. From the extreme low water mark to a few meters subtidally in rock pools and caves.

British Isles (SW coast of England and N and W coast of Ireland), and France (Roscoff, Iles de Glénan). There is a record from the northern Gulf of Mexico (Teerling 1975), but this has not been verified and is unlikely to be correct.

Named after Mrs. Buckland of Guernsey, who collected one of the type specimens (in fact the species should probably have been named “bucklandae” since the named person is female).

Bowerbank’s type specimen (a fragment, BMNH 1877.5.21.142, Fig. 2A) and slide (Bwbk. 542 ) and two of Carter’s (1871) types of Dercitus niger (BMNH 1895.4.27.1–6, Fig. 3A, and ZMB 3046) were reexamined (see also Table 1). Bowerbank’s material (Fig. 2) had calthrops with cladi 81–318 × 12–48 µm (cladome 120–480 µm), toxas 64–111 × 1–2 µm, and sanidasters 22–31 × 0.5–7. In the type material, the toxas showed some peculiar straight or curled side branches usually in the mid section (see below).

Carter’s type specimens (Fig. 3) possessed spicule sizes closely similar to those of Bowerbank’s type: calthrops 108–356 × 17–37 µm (cladome up to 472 µm), toxas 51–103 × 1.5–3 µm, sanidasters 21–31 × 3–7 µm. However, there was a curious discrepancy in shapes of calthrops and the sanidasters between the BMNH and ZMB Carter type specimens. Presumably this conveys a large variability among specimens from the same locality.

Topsent (1895) gives the following measurements of specimens from the W coast of France: calthrops with cladi 310–320 × 38–45 µm (thicker than the types), toxas 75–90 (similar to the types), sanidasters 21–27 µm (similar to the types).

In view of some of the discrepancies we considered it worthwhile to investigate whether spicular differences of specimens within the known range of the species would yield a pattern that could explain some of the differences. We compared spicular data from the northern samples cited above with those of samples from areas in the southern part of the range, from the coasts and offshore localities of Portugal obtained from Dr Joana Xavier and examined spicule sizes and shapes. This led us to the conclusion that there are consistent differences between samples from these areas which should be recognized at the subspecies level.

Holotype ZMA Por. 21810, Portugal, Gorringe Bank, Gettysburg Peak, 31–38 m, coll. J. Xavier, 2006 (cf. Xavier and Van Soest 2007, Figs 4A–E).

Additional specimens. Xavier collection, field nr. B05.09.36, Portugal, Berlengas Archipelago, Lagosteira, 7 m, 16–IX–2005, coll. J.R.B.T. Xavier.

Xavier collection, field nr. B05.09.59, Portugal, Berlengas Archipelago, Lagosteira, 6–7 m, 16–IX–2005, coll. J. Cristobo.

Xavier collection, Portugal, field nr. B05.09.98, Berlengas Archipelago, Lagosteira, 6 m, 18–IX–2005, coll. J.R.B.T. Xavier.

Xavier collection, field nr. B05.09.267, Portugal, Berlengas Archipelago, Gruta do Carreiro Maldito, 6–8 m, IX–2005, coll. A. Cunha.

Xavier collection, Portugal, field nr. A03/73, Arabida, Ponta da Passagem, 7 m, 16–VII–2003, coll. J.R.B.T. Xavier.

(Fig. 4A). Alive blackish outside and greyish inside (in alcohol chocolate brown throughout). Shape massively encrusting, flat with smooth surface, no apparent oscules; inhalant openings in sieve plates. Consistency cheesy, slightly compressible. A representative size of preserved specimens is 5×4×0.7 cm.

Skeleton: a layer of microscleres overlying a loose mass of calthrops megascleres. Spicular density appears lower than in the specimens from the British Isles.

Spicules: calthrops, toxas, sanidasters.

Calthrops (Fig. 4B), relatively uniform in size, cladi of irregular outline with endings irregularly stair-stepped and/or malformed, occasionally one or more cladi lacking; 58–108.3–165 × 5–14.6–27 µm, cladome 110–159.3–240 µm.

Toxa-like microscleres (Figs 4C–D), symmetrical, smooth, but slightly undulate / polytylote, with a shallow curve and evenly pointed; 37–51.3–69× 0.5–0.7–1.5 µm.

Sanidasters (Fig. 4E), rather uniform in size and shape, spines relatively long and thin, occasionally with a somewhat irregular shape; 16–19.3–24 × 0.5–2.4–6 µm (including spines).

Encrusting, typically bridging crevices and gaps in the substrate, sublittoral down to 6–38 m.

Portuguese main coast, Berlengas Islands, Gorringe Seamount. Furthermore, there are reports from the north coast of Spain (Ferrer-Hernandez, 1918; Babio & Gondar, 1978 (not seen); Acuña et al. 1984 (not seen). There is also a record from the Alboran Sea (Western Mediterranean) by Templado et al. 1986.

The spicule measurements of the present specimens are generally significantly smaller than those provided by most previous authors (Table 1), which is especially clear in the sizes of the toxiform microscleres: 51–111 × 1.5–3 µm in the subspecies bucklandi, 42–69 × 0.5–1.5 µm in the samples of the new subspecies, compared in Fig. 5: with bucklandi bucklandi toxas in Figs 5a–e and bucklandi lusitanicus ssp.n. toxas in Figs 5f–j. Possibly, the southern samples may be distinguished at the species level from the northern samples, but in view of the fact that there is an overall strong similarity with Dercitus bucklandi, we prefer to recognize only subspecies.

The toxa–like microscleres of Dercitus bucklandi s.l. are unique in the Astrophorida. They have been called ‘toxa’ because of the similarity in shape to similar microscleres in microcionid and mycalid Poecilosclerida. However, the resemblance is probably superficial and it is unlikely that these are homologous spicule types. There are subtle differences mostly only clearly visible in SEM images, such as the tendency to become apically swollen, and an overall faint ‘polytyly’ (Fig. 4D), and – at least in the Bowerbank type material of the nominal subspecies – the not infrequent presence of peculiar side branches or single long spines near the curved part in the middle. Possibly, this indicates that the microsclere derives from an end to end fusion of two incipient smooth microxeas – a more likely assumption than Topsent’s (1895) suggestion that the toxas are modified asters –, but firm proof for this hypothesis is wanting. Smooth microxeas are relatively common in several ancorinid genera.

Dercitus with a single microsclere category in the form of irregular sanidasters.

Samus simplex Carter, 1880.

BMNH 1931.1.1.31a, Invisible Bank, Andaman Islands, slide only of which it is uncertain whether it represents the present species. Type: Indian Museum Calcutta ? (not seen).

(from Carter and Sollas). “Sponge excavating. Spicules: Megasclere dichotriaene, rhabdome 0.210 × 0.042 mm. Microsclere rod-like with numerous small spines 0.0127 mm in length. Habitat: Gulf of Manaar”.

The exact properties and variation of this species have not been established so far, so we can only provide a discussion pending a proper revision. The type material has not been reexamined and its precise whereabouts are uncertain.

Annandale (1915) described specimens from the Mergui Archipelago (now Myanmar) as similarly ‘excavating’ (they are insinuating dead corals and filling spaces presumably made by clionaid sponges) and having dichocalthrops, and a single calthrops, as megascleres (sizes not given); sanidasters 16.2 µm.

Thomas (1972) described ‘coral boring’ material from the Gulf of Manaar, insinuating, with dichocalthrops having protocladi 33×2, deuterocladi 79×16, rhabdome 63×16 and cladome 210 µm. The rhabdome is clearly shorter than in the other described specimens.

In contrast to previous descriptions, Thiele (1900) recorded this species from Ternate (Indonesia, Halmahera) as forming a black encrustation likened to Dercitus (Dercitus) bucklandi. Spicule dimensions provided were: rhabdome of dichocalthrops 150 × 25 µm, cladome also similar in size, sanidasters 9 µm, provided with ‘numerous clear spines’. Thiele also mentions the presence of large (12–35 µm) pigment cells.

Maldonado (2002) gave a description of an Indian specimen from the Andaman Islands, supposedly of this species, but not the Gulf of Manaar type specimen itself. It is presumed that he described the specimen mentioned in Burton and Rao (1932). We borrowed the same slide from the NHM collection (BMNH 31.1.1.31a). It is possible that this specimen which according to Burton and Rao (l.c.) in external form resembled Dendy’s (1905) Dercitus (Stoeba) extensus more than Dercitus (Stoeba) simplex may indeed have been of another species as there is a big difference between the original description of Carter and the Burton and Rao slide in the size of the microrhabds: 12.7 µm in the type, 18–28 × 3–7 µm in the Andaman specimen (Fig. 6B). The rhabd of the dichocalthrops of the type is given as 210 × 42 µm whereas Maldonado gives 40–225 × 60–75 µm in the Andaman specimen (remeasured by us 75–251.5–317 × 12–39.8–52 µm) (Fig. 6A). Maldonado additionally gives protocladi as 30–50 × 12–60 µm (remeasured by us: 53–84.3–117 × 14–39.7–51) and deuterocladi as up to 150 × 35–40 µm (remeasured 15–105.0–157 × 8–29.4–38 µm). Cladomes 128–386.8–492 µm. Small dichocalthrops were rare in the slide.

If all these specimens are members of a single species, then it occurs on both sides of the Gulf of Bengal as well as on the islands in the middle of it and to the east into Indonesia. However, specimens need to be reexamined.

Holotype MNHN DT 3635, labeled “Corticium plicatum Schmidt 1868 no. 96” (there is also a slide – not examined - with Schmidt’s handwriting, bearing the date 1868); schizotype BMNH 1868.3.2.1. (slide), labeled “Corticium plicatum Schmidt, 1868, Calcabrina plicata, Algiers 1868”.

Additional specimen ZMA Por. 15101a, Banyuls, ‘coralligène’, 42.4833°N; 3.138°E, 10 m, coll. S. Groot, 10 August 1981.

The wet holotype (Fig. 6C) consists of two pieces, one small brownish mass of 2×2 cm, the actual specimen, and a larger limestone mass covered with bryozoans which does not appear to contain any additional sponge material but is presumed to be part of the substratum on which the sponge grew. The holotype is slightly fleshy, and in cross section consists of an outer layer of sanidasters overlying a dense confused mass of calthrops. Later descriptions (e.g. Topsent 1895) diagnose this species as encrusting and insinuating between stones and calcareous algae. Colour white, interior yellowish. Consistency firm, collagenous. Surface smooth with single oscules elevated into small conical papillae. Numerous large cells with inclusions (70 µm).

Spiculation of the holotype (Figs 6E-F, Table 2): Calthrops, dichocalthrops, sanidasters.

Calthrops (Fig. 6E) are dominating the megasclere complement, in a wide size range, but not divisible in size classes, most are regular four-claded equal-length spicules, a few three-claded occur and occasionally cladi are a bit crooked, cladi 41–101.0–188 × 3–14.7–29 µm, cladomes 57–154.4–252 µm.

Dichocalthrops (Fig. 6E), relatively rare, only a dozen were encountered in the spicule slide made from the holotype, invariably smaller than the biggest calthrops; infrequent incipient dichocalthrops, were encountered, with only two or one of the cladi bifid. Size of protocladi 20–22.4–28 × 4–5.6–8 µm, deuterocladi 15–28.0–36 × 2–3.6–6 µm, rhabds 28–45.6–57 × 3–5.6–9 µm, and cladomes 67–86.8–105 µm.

Sanidasters (Fig. 6F) are slightly fusiform and profusedly spined, relatively uniform in shape and size, 11–14.9–19 × 1–1.65–2 µm.

Additionally, we observed some oxeas of uniform size, approximately 150 × 3–4 µm, assumed to be foreign to the sponge.

Description of the BMNH Schmidt’s type slide (Fig. 6D, Table 2). The spicules (calthrops, dichocalthrops and sanidasters) are dissociated, but even in that condition it can be concluded that the slide is almost certainly taken from the holotype as the frequencies of occurrence and the sizes of the spicules are very similar to those of the holotype. Calthrops dominate the megascleres (Fig. 6C); most are regular, but occasionally some are three-claded or rarely two-claded. Endings of the cladi may occasionally be abruptly bent, bifid, indicating incipient dichocalthrops. They occur in a large size range, cladi 36–183 × 4–28 µm, cladomes 62–258 µm, almost identical in range to the spicules measured from the holotype. Dichocalthrops rare, as the slide contained only four measurable dichocalthrops, protocladi 15–21 × 3.5–10 µm, deuterocladi 21–33 × 3–8 µm, rhabds 73–95 µm, cladomes 36–45 µm. Sanidasters 11–18 × 1–2.5 µm.

The only non-type specimen available to us, ZMA Por. 15101 from Banyuls has spiculation closely similar to the type material (Table 2). Only the sanidasters appear on average slightly longer and more robust.

Encrusting and insinuating in crevices, large depth range down to 100 m.

Originally reported from Algeria. Elsewhere reported with certainty from Banyuls, Naples and the Adriatic. Possibly some of the records from the adjacent North Atlantic (Lévi and Vacelet 1958; Boury-Esnault and Lopes 1985) also refer to the present species, but see below.

Spicule dimensions of reported specimens are presented in Table 2. Sollas (1888), Lendenfeld (1894) and Pulitzer-Finali (1972) give unusually small calthrops (cladi 60–80 µm). Sollas (1888) and Lendenfeld (1894) additionally give very small sanidasters (8.3 and 6–7 µm). Topsent (1895) gives spicule data for this species as follows: calthrops with cladi 170–200 µm; dichocalthrops with similar sized cladi, with rabd thickness 25–30 µm; sanidasters 12–15 × 2–3 µm. Pulitzer-Finali (1983) reports this species from various Western Mediterranean localities and depths 1–100 m. Colours reported were white, pink, violet and brown. Both calthrops (cladi 40–200 µm) and dichocalthrops (cladome 60–210 µm) were present in variable quantities. Sanidasters varied between 10 and 20 µm. Pansini (1987) reports white specimens from the Alboran Sea lacking dichotriaenes, but provided no further data. It is possible this record concerns Dercitus (Stoeba) senegalensis sp. n. (see below).

Dercitus (Stoeba) plicatus is apparently quite variable and this may have led to widespread reports of the species from various East Atlantic localities, but also from Malaysia (Sollas 1902), Gulf of Mannar (Thomas 1970), Maldives (Calcinai et al. 2000), and Fiji (Tendal 1969).

We believe alleged records of this species outside the Mediterranean (Table 2) need to be reviewed critically on the basis of reexamination of the specimens. We have done so for material available to us from West African and Fijian localities (see below). In these specimens we found important differences with Mediterranean Dercitus (Stoeba) plicatus, which led us to assign them to three new species. It is likely that further records from e.g. Indo-West Pacific localities which we could not verify are part of a complex of Dercitus plicatus-like sister species distributed over most of the warmer parts of the oceans.

Several species of Dercitus (Stoeba) were synonymized with the present species by various authors, including the type species Dercitus (Stoeba) simplex. In most cases these synonymies are not accepted by us.

Syntype fragment ZMB 2409, dredged near Lesina, Croatia.

Encrusting and insinuating among stones and coralline algae, with oscular elevations. The fragment examined by us was a thin rounded papilla-like extension (probably from the larger of the two type specimens described by Lendenfeld). Consistency slightly rubbery. Colour (alcohol) orange.

Skeleton: at the surface consisting of a dense crust of microscleres, subdermally the skeleton consists of a mass of calthrops, embedded in a fibrous-organic groundmass.

Spicules: calthrops, dichocalthrops and sanidasters, no complete oxeas are found in the fragment examined, but a few broken monaxones were present.

Calthrops (Fig. 7A), with occasional bifid cladus endings, cladi 92–130.9–165 × 14–21.3–31 µm (Lendenfeld: up to 160 × 40 µm), cladomes 180–210 µm.

Dichocalthrops (Fig. 7B), rare, small, mentioned by Lendenfeld, but no measurements given. Our preparations contained a few, with protocladi 16–18 × 3–8 µm, deuterocladi 15–32 × 3–6 mm, cladome diameters 70–74 µm, rhabdi 40–47 µm.

Sanidasters (Figs 7C–D), with short low spination, size 11–15.2–18 × 2–2.45–3 µm (Lendenfeld: 12–15 × 1.6 µm).

No data.

Adriatic. So far there is only a single record of this species.

A major difference with the original description is the lack of giant oxeas (4000 × 70 µm), some centrotylote, reported and pictured by Lendenfeld (1894); also tylostyles and strongyles were reported. The fragment of the type specimen received from ZMB did not contain any such spicules, except for some broken fragments. For Maldonado (2002) the alleged presence of oxeas in a species otherwise considered by him a typical Stoeba was the reason to accept species with structural monaxone megascleres within the definition of Stoeba. We maintain that such spicules, if they would be proper, are auxiliary, not structural.

This species is similar in most respects to Dercitus (Stoeba) plicatus, but the orange colour has not been reported for that species (although Pulitzer-Finali (1983) mentions brown specimens of Dercitus (Stoeba) plicatus). Based on our observations of the sanidasters, it is possible that these are slightly different from Dercitus (Stoeba) plicatus in spination, with the latter having more profused spines. In view of this, we are forced to retain Dercitus (Stoeba) lesinensis as a valid species for the time being.

None (no response from an online form request to the Stazione Zoologica, Naples).

(from Sarà 1959). Numerous specimens (but only one was preserved, the holotype GG907, present whereabouts unknown) in a cave, depth 0–7 m, 30 m from the entrance. Whitish encrustations filling interstices between oysters and barnacles. Individual size 1–6 cm2, total size of all specimens 43 cm2.

Skeleton: no data.

Spicules: calthrops, dichocalthrops, sanidasters, oxeas (but see discussion).

Calthrops with the fourth cladus often shorter, occasionally triactines, cladi 45–175 × 5–21 µm.

Dichocalthrops, cladome 77–102 µm, thickness of cladi 3.5–6 µm, no individual proto-, deuteroclad or rhabd measurements provided.

Sanidasters, amphiaster-like with spines concentrated on both sides, length 8–15 µm, thickness 3–4 µm (with spines) 0.7–1.5 µm (without spines).

Oxeas, extreme size variation, 65–930 × 1.8–21 µm, no indication what their structural position is within the sponge.

Habitat. In shallow-water caves.

Distribution. Naples, Italy.

Remarks. Because no material has been examined and previous authors assigned this to Stoeba we retain this as a valid species of Dercitus (Stoeba) for the time being on account of the reported oxeas. However, apart from the oxeas the description perfectly fits that of Dercitus (Stoeba) plicatus (Schmidt, 1862) (see above). Especially the white colour, the Mediterranean occurrence and the combined presence of dichocalthrops and calthrops are telltale signs that they could be conspecific.

Holotype ZMA Por. 21530, off the coast of Senegal, coll. F.P. Vermeulen, 1906, fish trawl.

Paratype ZMA 06721, Mauritania, off Banc d’Arguin, 19.0667°N; 16.4167°W, dredged at 12–18 m, coll. R.W.M. Van Soest, R.V.’Tyro’ Mauritania II Expedition stat. 049, 11 June 1988.

Additional (non-type) material ZMA Por. 21697, Aegean Sea, fragment of specimen nr. 101 of E. Voultsiadou’s collections.

(Figs 8A, 9A). Sponge encrusting and agglutinating calcareous fragments, colour dirty white. Lateral size approx. 5×3 cm. The holotype now consist of three fragmented pieces, the paratype is 1.5×1.5 cm. Consistency crumbly.

Skeleton: a confused mass of calthrops with a crust of microscleres at the surface.

Spicules: calthrops (no dichocalthrops) and sanidasters.

Calthrops (Figs 8B, 9B–C), often with bifid or bluntly rounded cladi, occasionally five-claded, in a wide size range but upper size relatively large, cladi length and thickness 92–299.8–426 × 8–38.6–55 µm (in holotype) and 36–224.9–480 × 6–28.6–60 µm, cladomes 126–462.6–618 µm (holotype) and 61–300.4–810 µm (paratype).

Sanidasters (Figs 8C, 9D), relatively uniform in size and spination, relatively small: 11–12.6–17 µm (holotype) and 12–17.3–21 µm (paratype).

Named after the locality of the holotype.

Consolidating coarse limestone fragments on rubble bottoms.

Senegal, Mauritania, possibly (Eastern) Mediterranean.

The new species was formerly identified as Dercitus (Stoeba) plicatus, but it differs clearly by the much larger upper size of the calthrops and the apparent absence of dichocalthrops. There are some discrepancies between the two type specimens in the average size and thickness of the spicules, but in view of the generally large size variation this is considered intraspecific variation. It is likely that Lévi’s Senegal record of Dercitus plicatus also fits with this species, as it was similarly white coloured, and also lacked dichocalthrops. The size of the cladi of the calthrops were given as maximum 250 × 30 µm which is clearly larger than in Mediterranean Dercitus plicatus and within the range of our new species.

The ZMA collection contains a tiny fragment of a specimen from the Aegean Sea donated by E. Voultsiadou (ZMA 21697) which has calthrops (Fig. 9E) with cladi up to 295 × 48 µm (cladomes up to 475 µm), and which lacked dichocalthrops. Sanidasters similar in size and shape to those of Dercitus (Stoeba) senegalensis sp. n., especially to the paratype. Apart from the wide geographic separation, this fits with our new species.

The record of Pansini (1987) of Dercitus plicatus from the Alboran Sea possibly also belongs to this species as it was noted to lack dichotriaenes. However, since no further data were provided this remains undecided.

Holotype ZMA Por. 07521b, Cape Verde Islands, São Nicolau, Branco, 16.6667°N; 24.7167°W, dredged from 98 m, coll. R.W.M. Van Soest, HMS ‘Tydemann’ CANCAP VII Expedition stat. 156, 5 September 1986.

(Fig. 10A). Encrusting sponge, agglutinating and consolidating limestone fragments (dead corallines and serpulids), pale yellow-coloured, with cartilaginous consistency. Growing together with a yellow-coloured Chaetodoryx sp. Size of agglutinated mass approx. 4×2 cm.

Skeleton: a confused mass of dichocalthrops with a thin crust of sanidasters.

Spicules: dichocalthrops (no calthrops), sanidasters.

Dichocalthrops (Fig. 10B) relatively large, regularly shaped, with limited size variation, protocladi more or less uniform in smaller and larger spicules, but deuterocladi longer in larger ones: protocladi 42–48.2–56 × 9–21.6–35 µm, deuterocladi 23–106.8–204 × 4–17.2–29 µm, rhabdomes 71–170.6–252 × 8–21.0–31 µm, cladomes 132–294.6–475 µm.

Sanidasters relatively small, little variation in spination and ornamentation, 11–13.3–16 µm.

Named after the type locality.

Deeper water, consolidating coarse sediment.

So far with certainty known only from the type locality. Possibly, Topsent’s 1928 record of Dercitus plicatus from Boavista also belongs to this species.

Although the specimen was originally identified with Dercitus plicatus, there are two compelling differences with that species: (1) there are no calthrops, whereas these are the dominant spicule in Dercitus (Stoeba) plicatus, and (2) the size of the dichocalthrops, especially the length of the deuterocladi, is up to twice that of Dercitus (Stoeba) plicatus.

BMNH 1907.2.1.5a, two slides from type, R.N. 167, Gulf of Mannaar, Sri Lanka.

(partially from Dendy, 1905). Encrusting extensively over calcareous algae and filling crevices, 4.5×3.3 cm in lateral expansion. Surface smooth, no apertures. Colour pale grey (alcohol). Consistency tough, fleshy. Dendy mentions the presence of large cells with inclusions (cystencytes) of 60 µm.

The two slides contain thin cross sections of the peripheral regions.

Skeleton (Fig. 11A): irregular mass of short-shafted triaenes covered by a thin ectosomal crust of microscleres.

Spicules: megascleres predominantly dichocalthrops, but also normal calthrops or calthrops with one or two bifid cladi, sanidasters.

Calthrops (Fig. 11C), cladi 57– 87.0–123 × 8–14.9–23 µm, cladomes 108–158.9–210 µm.

Dichocalthrops (Fig. 11B), protocladi 39–46.9–54 × 5–15.5–21 µm, deuterocladi 8–37.9–61 × 4–11.1–18 µm, rhabds 24–65.6–124 × 5–15.1–27, cladomes 84–155.2–192 µm.

Sanidasters (Fig. 11D), oxea-like (Dendy: ‘microxeas’), 14–19.6–26 × 1–1.55–2 µm.

Encrusting calcareous algae at depths of 18–63 m.

Sri Lanka, ?Madagascar.

The spicule complement reminds of Dercitus (Stoeba) pauper Sollas (1902), but the cladi and rhabds of the triaenes in this species are distinctly thinner (5–27 µm in extensus, 3–10 µm in pauper), precluding synonymy of the two species for the time being, until variation of these features is better established.

It is likely that the record of Halina plicata of Thomas (1970) belonged to the present species as most descriptive remarks fit except for the upper size of the cladome (‘chord’) of the dichocalthrops which was quoted as 330 µm.

Vacelet and Vasseur (1971) reported this species from Madagascar. Live colour was noted as black, which was maintained in alcohol. Dichocalthrops measurements provided were: protocladi 20–40 µm, deuterocladi 60–80 µm, rhabds 150–180 µm. Sanidasters were 25–30 µm. No mention of calthrops. No further spicule data. The colour difference, lack of calthrops, and slight differences in spicule sizes and shapes render it doubtful whether this material belongs to Dercitus (Stoeba) extensus.

None. Holotype specimen, collected by R. Evans from Great Redang Island, Malaysia, could not be found in BMNH (2009).

(from Sollas, 1902). Sponge encrusting a dead coral fragment, 50×5×1–2 mm, surface smooth, shining; no oscules. Colour pink.

Spicules: Megascleres dominated by small dichocalthrops, but there are also small calthrops.

Calthrops have cladi of 60–70 × 3 µm (computed cladomes 90–115 µm diameter).

Dichocalthrops with protocladi 50–60 × 10 µm, deuterocladi 30 µm and rabdome 80 µm (computed cladomes 160–180 µm in diameter).

Sanidasters long and thin, with oxea-like shape: 15–20 × 1 µm.

Intertidal, occurring on dead coral fragments.

So far only known from Great Redang Island, one of the coral islands of the state of Trengganu at approx. 5°N on the E coast of Malaysia.

By the small size of the dichocalthrops this species appears similar to Dercitus (Stoeba) occultus (see below), but that species lacks calthrops, and details of spiculation appear different (longer protocladi and shorter deuterocladi in Dercitus (Stoeba) pauper). Dercitus (Halinastra) sibogae sp. n. (see below) also has small dichocalthrops, but this likewise lacks calthrops and the microscleres are differentiated in long and thin and short and fat sanidasters, not reported for Dercitus (Stoeba) pauper. All three species are tropical shallow-water sponges occurring in West Pacific – East Indian Ocean waters.

None. The type material collected by Michaelsen & Hartmeyer from Shark Bay, West Australia could not be found in ZMB (listed as a slide ZMB 4492 in Hooper and Wiedenmayer, 1994: 324).

(from Hentschel, 1909). Endolithic within corals, filling tubular cavities of 1–2 mm diameter which connect to the outside in only a few places. Colour (in alcohol) a deep brown. The skeleton consists of dichocalthrops and sanidasters.

Dichocalthrops relatively small, protocladi 20–28 µm, deuterocladi 50–92 µm, rhabd 86–105 × 12–18 µm (computed cladome diameter 130–230 µm).

Sanidasters 13–21 × 1.5 µm. Spines are described as strongly developed and irregular, but only tiny drawings of these spicules are provided, which only show elongated rhabd shapes.

An endolithic species from shallow coral reefs (0.5–3.5 m).

West Australia, Shark Bay, shallow water.

In spicule size this species appears close to Dercitus (Halinastra) sibogae sp. n. (see below), but that species has both ‘normal’ and compressed sanidasters, and it is epilithic. Details of the cladi lengths of the megascleres are also different.

The only other species of Dercitus (Stoeba) from Australian waters, Dercitus (Stoeba) xanthus Sutcliffe et al. 2010, differs sharply from the present species in the absence of dichocalthrops, in stead of which there are exclusively three-claded calthrops megascleres.

Holotype ZMUC unnumbered, Fiji Islands, Vitu Levu, Suva Harbour, coll. T. Wolff, 18 May 1965.

According to Tendal (1969) the sponge formed an irregular mass of 2×5×4 mm, situated in a crevice in a dead piece of coral. Smooth surface. Colour dark grey, oscules and pores not visible. Consistency hard. The material available to us consisted of a tiny fragment, approx. 1 mm3, half of which was sacrificed for SEM and a residue spicule slide.

Skeleton: unknown but presumably confused, with an ectosomal cover of microscleres.

Spicules: calthrops and dichocalthrops megascleres in approximately equal quantities, sanidasters.

Calthrops (Fig. 12A), with cladi occasionally crooked or bifid at the apex, size relatively uniform with few smaller spicules, cladi 96–222.7–258 × 19–31.2–37 µm, cladome 186–347.1–420 µm.

Dichocalthrops (Fig. 12B), with smaller sizes normal shaped, but characteristically with very short protocladi and long conical deuterocladi when larger, protocladi 19–26.5–30 × 13–25.2–42 µm, deuterocladi 55–112.5–192 × 9–20.2–31 µm, rhabdomes 58–84.6–132 × 11–13.6–21 µm, and cladomes 129–248.4–361 µm.

Sanidasters (Fig. 12C), relatively thick, pointed-fusiform at low magnifications, in SEM mostly with blunt endings, relatively uniform in size and shape, 15–16.9–21 × 3–3.6–4 µm.

Named after its type locality.

Shallow-water, in crevices in dead corals.

Known only from the Fijian type locality.

The distinctive feature of this new species, apart from details of spicule sizes, is the characteristic shape of the larger dichotriaenes with very short protocladi and long conical deuterocladi (represented most clearly in the dichocalthops at the right of Fig. 12B). Tendal (1969) assigned this material to Dercitus (Stoeba) plicatus (as Halina), but this Mediterranean species has much smaller dichocalthrops (cladomes only up to approx. 200 µm) in a lower quantity than the calthrops, and is white in colour. Tendal’s measurements of the spicules differs slightly from our measurements. We did not see any sanidasters thinner than approx. 3 µm, whereas Tendal mentions 1–4 µm in thickness and protocladi of the dichocalthrops were never longer than 30 µm, whereas Tendal gives 24–66 µm. Possibly, the limited size of our fragment and the few spicules we could measure explains the differences. Even with Tendal’s measurements included, the differences with Dercitus (Stoeba) plicatus in the size of the dichocalthrops and calthrops remain clear. Furthermore, Tendal stressed that the deuterocladi are always longer than the protocladi and gave an excellent drawing of the characteristically shaped dichocalthrops. Thus the differences with Dercitus (Stoeba) plicatus are distinct and unambiguous.

The species closest to Dercitus (Stoeba) fijiensis sp. n. is probably Dercitus (Stoeba) extensus from Sri Lanka. Colour and other macroscopic features appear similar, as is the shape of the microscleres. Calthrops and dichocalthrops are slightly smaller (cladomes of both approx. 200 µm, against up to 400 and 300 µm respectively in Dercitus (Stoeba) fijiensis sp. n.). The characteristic shape of the dichocalthrops of Dercitus (Stoeba) fijiensis sp. n. is not found in Dercitus (Stoeba) extensus.

Dercitus (Stoeba) occultus Hentschel (1909) has its dichocalthrops shaped rather similarly to Dercitus (Stoeba) fijiensis sp. n. but cladome size is distinctly smaller; moreover this species lacks calthrops.

Other species with a complement of both calthrops and dichocalthrops, Dercitus (Stoeba) lesinensis, Dercitus (Stoeba) dissimilis, Dercitus (Stoeba) pauper, Dercitus (Stoeba) reptans, and Dercitus (Stoeba) bahamensis sp. n. likewise differ in (dicho-)calthrops size and shape.

Holotype USNM 43170, Galapagos Islands, Albemarle Island, 0–3 m, 0.25°S; 91.4833°W, coll. Anton Bruun Cruise 16–66139, 25 May 1966 (slides and fragments of the holotype are present in MHNG, nr. 18963). Paratype ZMA Por. 11215, three fragments from the same locality.

(from Desqueyroux-Faúndez and Van Soest 1997). Creeping branches encrusting corals. Surface micronulose, no oscules, whitish pink (preserved condition).

Skeleton: thick ectosomal crust of microscleres. Choanosomal skeleton confused mass of megascleres.

Spicules: calthrops, dichocalthrops, sanidasters. Some spicule types are remeasured to provide additional data and to correct a remarkable error in the original description.

Calthrops robust, variable in size, cladi 344–484–648 (remeasured 39–648) x 16–27–50 µm (remeasured 6–50 µm) (cladome up to 670 µm, remeasured 60–680 µm). The smaller calthrops category reported here is rare.

Dichocalthrops, or short-shafted dichotriaenes, small, cladome 156–164–170 µm (remeasured 141–154.5–180 µm), individual cladi up to 90 × 8–9 µm (remeasured: protocladi 27–33.8–36 × 9–10.4–12 µm; deuterocladi 35–47.2–69 × 6–8.2–11 µm; rhabds 57–74.5–106 × 9–11.0–12 µm).

Sanidasters: short and slim, with blunt apices. Remarkably, they were quoted to be 15–74 × 2–8 µm in size, but this is an obvious error. Remeasured they appear to be highly uniform in size and shape: 9–12.8–16 × 1–1.9–2.5 µm, which is also in accordance with the size and shape of the figured sanidaster (fig. 52).

Shallow water.

Only known from the Galapagos Islands.

By its large calthrops this species stands out among Dercitus species with a complement of small dichocalthrops. None of the extant species are morphologically close.

Holotype HBOI 23–VIII–85–1–49, (HBOM 003.00040), with schizoholotype fragment ZMA Por. 07782, Bahamas, New Providence Island, NW of Goulding Cay, 25.025°N; 77.583°W, 210 m, coll. K. Rinehart in the Johnson SeaLink submersible, 23 August 1985, don. S.A. Pomponi and M.C. Díaz.

Slippery smooth encrustation on dead coral (Fig. 13A); the present material (upper part of Fig. 13A) consists of three fragments of 12×10, 8×8 and 8×5 mm, of approx. 1–2 mm in thickness. The holotype (lower part of Fig. 13A) is a larger fragment of 7×6 cm (not examined). Colour bright red when alive, darker red in alcohol. Consistency gum-like, easy to cut.

Skeleton: a confused mass of short-shafted triaenes and sanidasters.

Spicules: calthrops-like short-shafted triaenes, dichocalthrops and sanidasters.

Calthrops (Figs 13B, D) showing a clear rhabd, longer than the cladi, which are frequently curved or undulated or bifid. Cladi 138–166.7–186 × 12–22.5–28 µm, cladomes 207–266.4–330 µm in diameter, rhabds 230–245.9–270 × 24–27.2–30 µm.

Regular symmetrical dichocalthrops (Figs 13C–D) occur less frequently; protocladi 18–29.0–35 µm and deuterocladi 57–68.1–105 × 12–14.1–18 µm, rhabdomes 70–141.0–180 × 12–20.7–30 µm, cladomes 143–197.9–266 µm.

Sanidasters (Fig. 13E) have an overall short and squat shape. They tend to be amphiaster-like with frequently more heavily spined apices; spines usually with secondary spines. Size 12–13.3–15 × 2–2.85–3.5 µm.

Named for its type locality.

Collected by submersible at 210 m depth.

Known only from the Bahamian type locality.

This is a Dercitus (Stoeba) species similar to Brazilian Dercitus (Stoeba) latex (Moraes & Muricy, 2007) in shape, colour and consistency. It differs clearly in possessing dichocalthrops and larger unequal-claded calthrops, and the sanidasters are also clearly shaped and sized differently (long and thin with simple spines in Dercitus (Stoeba) latex). The Bonaire Dercitus (Stoeba) specimen described below differs in being insinuating, lacking dichocalthrops and also having thin sanidasters with undivided rays. Dercitus (Halinastra) lutea (Pulitzer-Finali, 1986, see below) is yellow, lacks dichocalthrops and has compressed sanidasters in its spicule complement. Dercitus (Halinastra) arubensis sp. n. (see below) differs from the new species in lacking dichocalthrops and possessing thick smooth microrhabds.

None.

MNRJ 8559, Belmonte Islet Wall, São Pedro e São Paulo Archipelago, Brazil, 0.9167°N; 29.35°W, 30 m depth, coll. F. Moraes, 15 July 2004.

(from Moraes and Muricy 2007). Thickly encrusting to massive, reddish- brown (darker in preservation), surface smooth, ‘stretched’; oscules 0.5–3 mm, size up to 10×20 cm. Consistency firm, rubbery. Ectosome provided with spherulous cells and sanidaster microscleres, choanosome compact, with randomly dispersed calthrops.

Spicules. Calthrops 42–212 × 7.5–25 µm. Sanidasters 10–15 × 1 µm.

Vertical walls and overhangs, 4–30 m.

Offshore archipelagoes to the NE of Brazil.

The red colour is shared with Dercitus (Stoeba) bahamensis sp. n., but this has dichocalthrops and the spicule sizes are also different. Below we report an undescribed Dercitus (Stoeba) spec. from Bonaire for which insufficient material was left after making preparation. It differs in habit (insinuating) and spicule size (calthrops cladi smaller, only up to 186 ×16 µm, and sanidasters slightly larger, up to 18 × 1.5 µm). Cladi of calthrops of the Bonaire material are frequently bifid and some ?auxiliary oxeas were present in the slides. Nevertheless, similarities are close enough to reckon with the possibility that the two are conspecific members of a variable species.

None.

USNM 21438, United States, California, Laguna Beach, coll. M.W. De Laubenfels, 26 March 1929.

(from De Laubenfels, 1932). Consolidating sandy substrate, shape ‘amorphous’, colour ‘drab’, surface smooth, consistency slimy. Size of parts containing the characteristic spiculation 0.2–2 mm. Skeleton of interior ‘packed’ with megascleres and microscleres.

Spicules: calthrops and sanidasters.

Calthrops, small, often reduced to ‘tripods’, cladi 25–65–80 × 3–8–10 µm.

Sanidasters variable in spination, often concentrated in two areas of the microsclere to approach an amphiaster condition, but many are irregular, endings blunt, 8–12 µm.

Intertidal.

California.

De Laubenfels (1932) mentions the possible presence of toxas, judged to be foreign. Lee et al. (2007) provide SEM photos of the spicules. The species stands out by its small calthrops, which is only shared with Dercitus (Stoeba) xanthus, but in that species there are no normal calthrops, only three-claded ones, and the sanidasters are considerebaly longer.

None.

QMG329976 (SBD513022), south of Rock Cod Shoal, off Gladstone, Great Barrier Reef, 23.725°S; 151.6647°E, 34 m depth, epibenthic sled, coll. FRV ‘Lady Basten’, 20 September 2004.

(from Sutcliffe et al. 2010). A thin sponge agglutinating biogenic rubble such as remains of worm tubes, gastropods and bivalves. Usually fist-sized or smaller. Live color red to yellow, surface uneven, no visible oscules.

Spicules: three-claded calthrops and sanidasters.

Calthrops small, divisible in two size classes with means of approximately 25 and 72 µm. Only 20% of the 163 specimens recorded possessed calthrops, usually in high densities, in the remaining 80 % these spicules were lacking. Sanidasters universally present in all specimens, displaying a wide variation in length and width, 10–20 × 1–2.5 µm, densely spined with relatively short spines up to 1 µm.

Sandy bottoms between 16 and 86 m depth.

Great Barrier Reef, occurring over the entire range.

As Sutcliffe et al. (2010) point out, there is only one species among the Dercitus s.l. species that is similar, viz. Dercitus (Stoeba) syrmatitus, sharing the possession of three-claded calthrops, the small size of the calthrops and the agglutinating habit. The differences are nevertheless quite clear and compelling, the rarity of the megascleres, the lack of normal fourc-claded calthrops and the distinctly larger sanidasters.

The only other Australian record of the genus, Dercitus (Stoeba) occultus, from West Australia, differs sharply in having exclusively dichocalthrops megascleres.

None.

(from Vacelet and Vasseur 1971). Encrusting the underside of coral blocks, 2–3 cm2 in expansion; consistency soft; live colour yellow, white in alcohol.

Spicules: calthrops, sanidasters, ?strongyles.

Calthrops with irregular cladi, 50–250 × 15–25 µm.

Sanidasters short and fat, 12.5 × 2.5 µm.

Strongyles, probably foreign, long and thin 375–400 × 3–5 µm.

Shallow reefs.

Known only from the Tuléar area, Madagascar.

Live colour and the details of the spicules make it likely that this is an undescribed species. The strongyles are considered foreign as the authors themselves suggested.

ZMA Por. 08985, Netherlands Antilles, Bonaire, W coast, near Kralendijk, in reef caves, 12–43 m, 12.15°N; 68.278°W, 1984, coll. D.R. Kobluk.

Insinuating in coral crevices, in reef caves between 10 and 40 m depth. The available sponge material has been ‘used up’ entirely for the initial slides from which the genus identification (as Dercitus) was made. Properties of the sponge and structure of the skeleton cannot be accurately described. The skeleton is a confused, dense mass of calthrops megascleres on the outside covered by a layer of microscleres. These are also common throughout the sponge body. Spicules are simple calthrops and sanidasters.

Calthrops regular, with four equal cladi, which may occasionally be curved; endings occasionally bifid or irregularly terminally knobbed, but no true dichotriaene nor triactine modifications are present; sizes highly variable, cladi 39–102.3–186 × 4–9.8–16 µm, cladomes ranging 58–159.7–288 µm.

Sanidasters, thin, 12–14.8–18 × 0.5–0.76–1.5 µm.

In reef caves at the deeper parts of fringing reefs.

Kobluk and Van Soest (1989) reported a few oxeas of 600 µm length, which are here considered foreign, and ‘dichotriaene-like variations’ by which they meant the calthrops with bifid cladi, not to be confused with true dichocalthrops. Since no proper specimen was left, no SEM observations of the spicules of this species could be made. It is likely that it is an undescribed species. It differs from Central West Atlantic Dercitus (Stoeba) latex (Moraes & Muricy, 2007) in habit (encrusting in latex), and spicule size (calthrops cladi larger, up to 212 × 25 µm, and sanidasters smaller, up to 15 × 1 µm). Dercitus (Stoeba) bahamensis sp. n. likewise is encrusting and it has dichocalthrops and thicker sanidasters (see above).

Dercitus with clear subdivision of the sanidaster microscleres into longer, thinner irregular sanidasters and shorter, fatter, compressed, often aster-like forms.

Pachastrella exostotica Schmidt, 1868 (by original designation).

Holotype, ZMB 287, Eritrea, Dahlak Archipelago, near Perim Island, Red Sea, 16.75°N; 40.05°E, 52 m, coll. Siemens.

Black mass (in alcohol) of 3×3×0.5 cm (Fig. 14A). Surface irregular granulated, grooved, no apparent oscules. In cross section, only the surface region is darkly pigmented, but the choanosome is much lighter coloured. According to Keller choanocyte chambers are crowded in the lower parts of the choanosome, size 25 µm.

Skeleton: a confused, dense mass of calthrops with a cover of microscleres at the surface. A few oxeas of widely different sizes were noted by Keller, but these were limited between approx. 100–120 × 2.5 µm of a typical haplosclerid type, in the slide examined by us.

Spicules: calthrops, sanidasters, compressed sanidasters (pseudasters).

Calthrops (Fig. 14B), generally regularly shaped, in a wide size range, usually with one of the cladi slightly longer than the other three (short-shafted triaenes): 45–128.2–275 × 5–18.2–35 µm.

Sanidasters (Fig. 14C), variable in thickness and spination, but relatively uniform in length, generally ‘stocky’, 15–23.1–27.5 × 2.5–5.3–7.5 µm.

Compressed sanidasters (pseudasters) (Fig. 14D), globular, irregular in shape (Keller called these ‘Sterraster oder Sphaeraster’), 7.5–10.5–12.5 µm in diameter.

Deeper water, beyond the reefs

Known only from the Southern Red Sea.

Schmidt (1868) gave hardly any description (some vague remarks on the megascleres of Pachastrella monilifera grading into a statement on the Red Sea specimen), but the drawings of the microscleres show a sanidaster and a globular aster. Keller claims to have had access to Schmidt’s type specimen, but he faithfully reports that there is a discrepancy between Schmidt’s original label and the label of his redescribed specimen, e.g. the original collector was stated to be Ehrenberg by Schmidt, but Keller states it is Siemens, which is probably the correct one.

Maldonado (2002) assigned Pachastrella exostotica to the genus Stoeba and declared Halinastra a junior synonym of that genus. However, he possibly overlooked that Pulitzer-Finali’s (1986) Pachataxa lutea possesses similar spiculation as Pachataxa exostotica (see below). With at least two species sharing the peculiar aster-like compressed acanthorhabds, (and several further species with diversified aster shapes, see below) there is good reason to maintain Halinastra as a distinct taxon, proposed here to be a subgenus.

Holotype RMNH 4256, Indonesia, Kalimantan, Berau region, Derawan Islands, depth 10 m, coll. N.J. De Voogd, field nr. BER105/140808/055, SCUBA, 14 August 2008.

Blackish grey lobate mass (Fig. 15A), approx. 20×15×10 cm in size, surface in places speckled white by ?coral sand and at the base the specimen is encrusted by a bluish sponge (Haliclona). Oscules prominent on the summit of lobes, approx. 0.5 cm in diameter. Consistency firm, compressible. The preserved specimen is broken into two similar sized masses (Figs 15B, 16A). The black colour is maintained in alcohol and has strongly darkened the fluid and the labels.

Skeleton: difficult to study in the preserved condition due to the intense black colour, but structure is dense and unorganized, with a dense cover of microscleres at the surface.

Spicules: calthrops, sanidasters and compressed spheraster-like microscleres (pseudasters); a few oxeas are present, but these belong to the encrusting Haliclona.

Calthrops (Fig. 16B), generally regular in shape and cladi number, occasionally three-claded or five-claded; size highly variable, cladi 25–151.4–280 × 5–17.2–35 µm.

Sanidasters (Fig. 16C) of extreme variability in shape, long thin with short spines, thicker with prominent stubby spines and squat warty ones, with many intermediates; size 19–29.1–42 × 1–5.1–10 (spines 0.5–2.2–4.5 µm).

Compressed sanidasters (pseudasters) (Fig. 16D), globular or oval with very short rays (usually less than 0.5 µm), diameter 8–11.4–15 µm.